Pump-impeller for washing machines



Nov. 22, 1955 Filed July 15, 1953 E. W. WILKINS PUMP-IMPELLER FOR WASHING MACHINES FIG. I.

2s 2 37 m M 3 Sheets-Sheet l Inventor Attorneys.

Nov. 22, 1955 E. w. WILKINS PUMP-IMPELLER FOR WASHING MACHINES Filed July 13, 1955 s Sheets-Sheet 2 x ll Aitorrzeys Nov. 22, 1955 w. WILKINS 2,724,255

PUMP-IMPELLER FOR WASHING MACHINES Filed July 15. 1953 a She ets-Sheet :s

FIG.6.

United States Patent Ofifice 2,724,255 Patented Nov. 22, 1955 p 2,724,255 PUMP-IMPELLER FOR WASHING MACHINES Edward W. Wilkins, Tettenhall, Wolverhampton, England, assignor to Wilkins & Mitchell Limited, Darlaston,

Stalfordshire, England t 1 Application Jul is, 1953, Serial No. 367,651

7 Claims. (11. 68-133) Thisjinv ention relates to washing machines of the kind in which a rotary disc-like impeller is provided in the base of the washing compartment, and is continuously rotated to agitate the washing liquid and circulate it through the articles placed therein.

According to the present invention the impeller is formed on its underside with a concentric inwardly facing annular channel .into which liquid is forced by centrifugal action and entrained, means being provided for collecting and drawing 01f under the action of its own position to draw otf liquid, from the channel, and said element, or a liquid flow conduit associated therewith, will incorporate a flow control valve or cock, whereby the discharge of liquid from the washing compartment can be effected when desired, or alternatively the element may be movable between the operative liquid draw-oft position, and an inoperative position in which the intake opening is not presented to the entrained liqiud in the channel of the impeller, means being provided for efiecting movement of the element between its operative and in operative positions.

, A preferred embodiment of the invention will now be described with reference to the accompanying drawings, inwhich:

Fig. .1 is a sectional side elevation of the lower portion of a washing machine.

' Fig. 2 is a plan view of the washing machine.

, Fig. 3 is a fragmentary plan view, to an enlarged scale, showing details of construction.

, Fig. 4 is a sectional view on the line 4-4 of Fig. 3.

. Fig. 5 is a front elevation of Fig. 3, certain parts being shown in section.

.Fig. 6 is a fragmentary sectional side elevation of a portion of the lower part of a washing machine, showing a modified form.

,Referring to the drawings, the impeller 10 is situated in the base 11 of the washing compartment 12 of the machine, which compartment is of generally square form in plan view, as seen in Fig. 2. t

The impeller is formed in anysuitable way, (for example as by spinning), as a disc-like plate member, the peripheral portion of which is turned over downwardly at 13 and then inwardly at 14, as seenmost clearly in Fig. 1, so that the impeller is of inverted dished shape with a continuous inwardly facing marginal annular channel 15 on its underside.

QThe impeller 10 is located as a fairly close fit in a cencircular recess 16 in the. base 11 of the washing compartment of the machine, and is secured to the upper end of a vertical spindle 17 rotatable in bearings 18. The bearings 18 are mounted in a sleeve 19 which depends centrally from a plate 11*, which plate forms the bottom of the recess 16 in the washing compartment base 11. The portion of the base 11 ofthe washing compartment surrounding the impeller is inclined upwardly and outwardly, and this inclination together with the square form of the washing compartment in plan view, produces a surging of the washing liquid during operation of the machine.

Radially disposed vanes 20 are formed on the upper surface of the impeller 10, in well-known manner, by pressing them out from the material of the impeller itself.

At the bottom end of the spindle 17 is secured a pulley 21, connected by a driving belt 22 with a second pulley 23 on the shaft of an electric motor 24 by means of which the impeller 10 is driven in rotation.

As the impeller rotates, the liquid beneath it is forced by centrifugal action into the channel 15 and entrained therein, that isto say, carried round in the channel as the impeller 10 rotates.

Beneath the impeller 10 is mounted the element for collecting and drawing off the liquid entrained in the channel, and said element consists of a pipe 25 which passes vertically through the bottom plate 11 of the recess 16 in which the impeller 10 is located, and near the edge thereof.

The pipe 25 is mounted in the plate 11 for pivoting about its own axis, and the upper end portion of the pipe is bent over at 26 so that it is substantially horizontal, the arrangement being such that the mouth 27 of the pipe can be swung into the channel 15 of the impeller 10, with the said mouth 27 facing against the direction of movement of the entrained liquid in the channel 15,

the result being that at normal working speeds of the impeller, (e. g. 400-600 revolutions per minute) liquid is forced into the intake opening afforded by the mouth 27 of the pipe 25, under pressure due to its own momentum, and drawn ofi? to waste through a flexible rubber hose 28 attached to and forming a continuation of. the pipe 25. t t

In order to cause the mouth 27 of the pipe 25 to face squarely against the direction of movement of liquid entrained in the channel 15, the end of the horizontal portion 26 of the pipe 25 may be inclined, as shown in Fig. 2, or alternatively, the horizontal portion 26 of the pipe may be curved appropriately in the horizontal plane, as shown in Fig. 3.

In Figs 1 and 2, and in Fig. 3, the vertical portion of the pipe 25 is journalled in a boss 29 on the underside of the plate 11*, which boss is formed with an integral downwardly projecting sleeve 30 of reduced diameter, (see particularly Fig. 4). The flexible hose 28 secured to the pipe 25 is expanded over this sleeve 30, and the end of the hose makes liquid-tight engagement with the face of the boss 29, the hose 28 being secured to the pipe 25, in this condition, by a cleat 31 which is provided with a handle extension 32. The handle 32 affords a means for pivoting the draw-off element between its operative position, in which the mouth 27 thereof is in the channel 15 of the impeller 10, and an inoperative position in which the mouth 27 is withdrawn from the channel 15, both these positions of the draw-off element being indicated in Fig. 2 of the drawings. 1

3 draw-off element in its respective operative and inoperative positions.

In the alternative construction shown in Fig. 6, like parts to those shown in Figs. 1-5 bear like reference nuinerals. The construction differs from that illustrated in Figures "1-5 in that the draw-otf-pipe 25 is fixed in position in the plate 11*, with the intake opening 27 in the channel 1'5 of the impeller 10, and a flow-control tap 39 is provided in the flexible hose 28 connected to the pipe 15, said tap '39 being mounted upon the wall of the machine where it can be operated readily to control the functioning of the impeller to pump liquid from the washing compartment.

In operation the impeller continues to function as a pump to empty the washing compartment until very little liquid remains therein, due to the inclination of the base 11 and the impeller 'being in a recess. Some liquid, however, tends to remain'upon the inclined base 11 of the compartmentdue to the centrifugal action of the rotating impeller. The quantity is so small that when the impeller is stopped this'residue drains into the recess 16 which houses the impeller, and can be discharged by restarting the impeller for a few revolutions. Any small quantity not discharged in this way is drained into the hose 28 by providing two small drain holes 37 (Figs. 3 and 4) in the wall of the pipe 25, just above the base 11 of therecess '16. Two upstanding arcuate blocks 38 provided on the plate 11 co-operate one with each of the drain holes '37 for closing them and operate as valves in that the holes 37 move away 'from the blocks 38 and to an open condition when the pipe 25 is pivoted to the inoperative position in which it is left after the machine has been used. Thus drainings from the walls of the washing compartment will drain into the discharging hose 28 through the open holes 37 while the machine is standing.

The considerable free space in the recess 16 beneath the impeller is utilized to house the element 39 of an electric immersion heater for the washing liquid, which heater is thus both in a protected position and also in the ideal position for heating the liquid.

Holes may be'provided in the impeller 10, if desired, either'near the centre or in the leading surfaces of the vanes 20, which holes tend in some measure to augment the supply of liquid from above the impeller to below it,

but these holes are not essential to the satisfactory operationof the impeller as a pump, and could have some detrimental efiect on garments being washed.

Having fully described my invention, what-I claim and desire to secureby Letters Patent is:

' "1. In a washing machine, a washing compartment having .a base, a disc-like impeller in said base, and'means for rotating said impeller continuously for circulating washing liquid, the combination of a concentric inwardly facing annular channel on said impeller and means for collecting and drawing oif, by the action of its own momentum, liquid entrained in said channel, whereby the impeller can function as a pump for discharging liquid from the washing compartment.

2. In a washing machine, a washing compartment having a base, a disc-like impeller in said base, and means for rotating said impeller continuously for circulating washing liquid, the combination of a concentric inwardly facing annularchannel on said impeller, a liquid intake element adjacent said impeller which presents an intake opening in the path of movement of liquid entrained in said channel, and liquid draw-off means connected with said intake element, whereby the rotating impeller can function as a pump to discharge liquid from the washing compartment.

-3-.*In a-washing machine, a'washing compartment having ia'ibase, adisc-like impeller in said base, and-means for rotating said impeller continuously for circulatingwashing'liquid, the combination of a concentric inwardly facing :anntrlar channel "on said impeller, a liquid intake ele- 4 ment adjacent said impeller having an intake opening presented in the path of movement of liquid entrained in said channel, a liquid draw-off conduit connected with said intake element and flow control means in said drawoff conduit.

4. In a washing machine, a washing compartment having a base, a disc-like impeller in 'said base, and means for rotating said impeller continuously for circulating washing liquid, the combination of a concentric inwardly facing annular channel on said impeller, a liquid intake element movably mounted in the base of the compartment adjacent said impeller and having aliquid intake opening,

means for moving said intake element between an operative position, in which said intake opening is presented in the path of movement of liquid entrained in said annular channel, and an inoperative position in which said opening is withdrawn from said channel, and a liquid draw-off conduit connected with said intake element, whereby the impeller can function optionally as a pump for discharging liquid from the washing compartment.

5. In a washing machine, the combination 'o'fa washing compartment having a circular recess in its base, a disc-like impeller in said recess and means for rotating said impeller continuously for circulating washing liquid in said compartment, a peripheral inwardly facing annular channel on'the underside of the impeller, a liquid intake element beneath the impellenwhich element is in the form of 'a shaped pipe comprising a horizontal portion, the mouth of which afiords a liquid intake opening, and a vertical portion which passes through the base of the recess, a bearing in said base which said vertical portion is turna'bly mounted, -a liquid draw-off conduit connected with said vertical portionya lever handle aifixed 'to' said vertical portion for moving said shaped pipe between an operative position, in which the said mouth is presented inthe path of movement of liquid entrainedin the annular channel, and an inoperative position in which "the mouth is withdrawn from said channel.

6. In a washing machine, the combination of a washing compartment having a circular recess in its base, a disclike impeller in said recess and means for rotating said impeller continuously for circulating washing liquid "in said compartment, a peripheral inwardly facing annular channel on the underside of the impeller, a liquid intake element beneath theimpeller, which element is 'in'the form of a shaped pipe comprising a horizontal portion, the mouth of which affords a liquid intake opening, and a verticalportion which passes through the base of the; recess, a bearingin said base in which said vertical portion is 'turnably mounted,a liquid draw-off conduit connected with said vertical portion, 'a lever handle alfixed to said vertical portion for moving said shaped pipe between an operativeposition, in which the said mouth is presented in the path of movement of'liquid entrained in the annular channel, and an inoperative position in which the mouth is withdrawn from said channel, a *bracket upstanding from the base of said recess, upon the upper edge of which bracket the said horizontal portion of the shaped pipe rides, and stops on said bracket defining the said operative and inoperative positions of said shaped pipe 7. A washing machine as claimed inclaim 6, andineluding at least one arcuate block upstanding from the base of said recess in face contact with the vertical portion of said shaped pipe, and a drain 'hole in said vertical portion, said block maskingand closing said drain hole when said pipe is in its operative position, which drain hole moves away from the block and into open condition when the shaped pipe is moved to its inoperative position; 7 References Cited inthe ,file of :this :patent UNITED STATES PATENTS 1,789,939 Geldhof Ian. 20, 193-1" FOREIGN PATENTS 683909 Great Britain Dec. 10, 1952 g 

